Laminated panel device having electroluminescent indicating areas



NOV, 12, 1963 H. c. s'ruERzL ETAL 3,110,882

LAMINATED PANEL DEVICE HAVING ELECTROLUMINESCENT INDICATING AREAS Filed April '7. 1961 2 Sheets-Sheet 1 l u l l I' Il l TORI 1 INVENTOR. fr C ferz f zfyQ/Q bf ATTORNEY fyi,

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NOV- 12, 1963 H. c. s'rUERzL ETAL 3,110,882

LAMINATEDPANEL DEVICE HAVING ELECTROLUMINESCENT INDICATING AREAS Filed April 7, 1961 2 Sheets-Sheet 2 ATTORNEY United States Patent O 3,119,882, LAMHNATED PANEL DEViCE HAVEN@ ELEGIR@- IUMHNESCENT iNDiCATiNG AREAS Henry C. Stuerzl and Hugh D. Wright, Flint, Mich., as-

signors to Generai Motors Corporation, Detroit, Mich.,

a corporation of Deiaware Eiied Apr. 7, 1961, Ser. No. 101,531 Claims. (Ci. 340-52) This invention relates to panel instrumentation and more particularly to laminated panel devices for giving one or more illuminated indications of speed, pressure, temperature or some other variable condition.

instrument panels such as used on automobiles and also on stationary installations often compris-e clusters of indicators and they are usually complex `arrangements embodying mechanical devices of proportions `which yare bulky in relation to space available. ff a revolution counter or speedometer is one iof the instruments, it adds to the complications because such `an instrument must be of such size as to give :an easily read reading over a large scale. illumination of digits by electroluminescence h-as been used effectively in a speedometer as taught in the United States Patent No. 2,858,632, granted November 4, 1958, in the names of M. J. Caserio and H. C. Stuerzl. The adaptation, however, necessitated the use of a mechanically actuated pointer to serve as a moving indicator. A speed warning device using a plurality of separately lighted indicia is disclosed in the United States Patent No. 2,504,582, granted April 18, 1950, in the name of D. I. Pugin. This latter adaptation, however, is bulky and not conducive to large and trouble-free production of esthetically -appealing instrument panels.

An object of the present invention is to provide a compact panel device capable of indicating one or more variable conditions without embodying, at the panel, any movable indicating mechanical part such as a pointer. Another object is to provide an esthetic panel device ernbodying one or more ind-icators and which may be quickly inserted in a `support mounting for electrical actuation by a signal or by signals originating elsewhere.

A feature of the present invention is a laminated panel device having multiple areas radapted to be illuminated in sequence as an indication of a variable condition. Another feature is an electroluminescent panel of compact dimensions and embodying a printed circuit pattern whereby discrete areas of the panel on its front .side may be illuminated in accordance with *a remote signal. Another feature is an electroluminescent panel bearing `a printed circuit pattern and which may be mounted as a unit on a support from which one or more electrical signals may be obtained to operate the panel without the use of any moving mechanical parts located at or on the panel.

These and other important `features of the invention will now be described in detail in the specification and then pointed out more particulmly in the appended claims.

In the drawings:

FIGURE l is la perspective view of portions of an automobile windshield cowl and instrument panel in which arrangement a panel device embodying the features of the present invention is installed;

FIGURE 2 is an elevation View of the panel device as shown in FIGURE l, the view being drawn to an cnlarged scale and showing the panel device las positioned above the supporting structure prior to its lowering for insertion into its operative position;

`FIGURE 3 is a sectional view drawn to a larger scale as seen looking in the direction of the arrows 3-3 in FIGURE 2 with the panel device lowered into its supported end and operative position;

FIGURE 4 is a sectional view looking in the direction of the arrows 4 4 in FIGURE 3;

*lliiz Patented Nov. l2, 1963 ice FIGURE 5 is an elevation view of a portion of the panel `as seen looking in the direction of the arrows 5-5 in FIGURE 3, the scale being somewhat reduced; and

FIGURE 6 is a view `of the panel device looking in the direction of the arrows `6 6 in FIGURE 3 and showing the printed circuit pattern, `the View being drawn to the same scaie as used in FIGURE 5.

`In FGURE l, a windshield 1t? is depicted as protecting a passenger compartment and an instrument panel 12 of .an automotive vehicle having a :steering col-umn 14. The panel i12 has built into it a support or housing 16 which serves as a source of signals to openate a panel device 18 which constitutes at least `a part of one embodiment of the present invention. The support 15 is als-o provided with an overhanging hood 19, the presence of which is not necessary -but which is preferred to enhance the appearance and effectiveness of the panel device 1S for daytime use as will be apparent.

In electroluminescent devices, a desi-red glow of a panel results from the application of a varying voltage across a sheet or coating .of fluorescent phosphor. If an alternating, pulsating, or othenwise varying current is used to eiiect a variable electrical field within rthe phosphor, an area of the latter material will glow visibly and may be plainly seen through a protective plate or sheet of transparent, tinted -o-r translucent glass or plastic. The illumination is uniform over the entire area and the amount of power consumed is small. In the present instance the creation of the eiective electrical field is not in one area but in a multiple number of areas in a single laminated panel making it possible to indicate a condition such as the -attainment of Ia given speed within a range of speeds and to do so without mechanical or moving indicator pointers and fthe like closely associated with the panel. With this in mind, it will be noted that the support 16 could have moving ymechanical devices within it and this is immaterial insofar as the present invention is concerned but i-t should be provided with circuit connections to adapt it subsequently Ito transmit suitable signals to the panel device 18. For an automobile speedometer the several speeds to be indicated would each necessitate a separate contact to receive a signal that the speed of that contact has been attained by the vehicle. A device for establishing a separate circuit for each speed may be a centrifugal switch such as disclosed in the United States Patent No. 1,647,374, granted November l, 1927, in the name of B. Robinson. Some other form of device may be used for this purpose and no further description is given herein regarding such device as it forms no part of the present invention. The arrangement, of course, should be such that successive circuits may be established or broken or made and broken dependent upon the elect desired.

A fuel gage panel may fbe energized by .successive circuits established by `a float operated switch operated at several predetermined liquid fuel levels and contacts for these circuits would be located in the support 16 together with the contacts for the speedometer.

Other gages, such as those indicating variations in oil level, oil pressure, high beam lights, brake application, generator charging, hot or cold temperature, may serve to impart signals in the form of electric current available at proper contacts within the support 16.

FEGURES 3 and 4 illustrate one manner of maintaininfr contacts within the support 16 for imparting signals to the panel device 18. A plastic elongated member 20 having an inverted U-shaped cross section is mounted within the support 1.6 and along and beneath a slot 22 formed in the top wall 24 of the support. Contacts 26 in the form of spring clips are each held by means of a conductive rivet 28 to a terminal 30 leading to the source of a particular signal. Some of the spring clips are grounded as will further appear.

The panel device includes a bezel or metal rim plate 32 dening an elongated opening 34 (FIGURE, 2) through which all the panel indicator readings may be observed. The rirn plate 32 is spaced by several blocxs such as the block 35 (FIGURE 3) from a rear metal plate 36. Screws (not shown) are utilized to retain this relation. Between the plates 32 and 36 enclosed a plastic window 4), a transparent plastic or glass protectorsheet 4Z, a coating of electroluminescent material lll-i covering discrete areas of a metal backing plate 46, and a dielectric or main supporting plate 4S.

integral with the rear metal plate 36 is a cover rim 5l? enclosing the space between the plates 32 and 36 and having its width extending forwardly and rearwardly beyond those plates. The rim Sti is adapted to overlap the rear margin of the hood i9 which is joined at its sides to the wall 2d. The slot Z2 extends along substantially the full width of the hood .i9 to receive depending parts of the panel device llo.

The main supporting plate d8 is preferably of plastic and is quite rigid so that two depending tongues SZ and 5d thereof may be pushed down into the spring clips 26 when the panel device lld is located as a unit on the support 16. A printed circuit pattern as shown in FIG- URE 6 is carried by the rear side of the plate 4S. lt comprises leads which extend upwardly from the bottom edges of the tongues 52 and 54. Most of the leads term"- nate along the top edge of the plate 4S for eilecting operation of the speedometer aspect. Conductive spring clips 56 are provided each of which connects a lead of the printed circuit pattern such as a lead SS to an area such as the area d@ (l miles per hour increment indication) or 65) (between l() mile increments) on the iront side of the metal plate 46. This area oil and oil is one of multiple discrete areas on the plate 4d which are covered by the electroluminescent material 44 as seen in FIGURE 5. Three holes 62 are provided in the lower margin of the plate i8 so that three screws and three spacing blocks such as the screw 64 and the block 66 (FIGURE 3) may be used to hold the plate 48 securely to the rim plate 32. Plastic sponge material is employed as at 68 and 7d to hold the clips d and the printed pattern clear of the rear plate 36.

The transparent protector sheet 42 covering the areas of material d4 is of such thickness that it clears a closely adjacent but spaced light -lter coating '72 on the rear side of the window 4d. This iilter 72, if made of a colored plastic (preferably blue, green or yellow) is extremely attractive and provides suitable contrast under daylight conditions when exterior parts such as the rim 5t? and the plate 32 are chromium finished with the hood 19 and the support lo painted blue. Other color combinations are, of course, suitable. A horizontal groove is formed in the window 4t? to retain a'silver colored strip of plastic 'i5 separating the speedometer viewing face of the panel from the lower condition indicators. The speedometer face has an arrowhead 7S exposed to view at each end. This arrowhead is of blue light iiltering material surrounded by an opaque or black paint with the material and paint being applied to the rear side of the plate 4t?. These arrowheads may be lighted to indicate a right or left turn for the vehicle as will be understood. The indicia in the over-all panel are formed by a illing of opaque white paint in grooves formed on the back side of the window dil.

The speedometer aspect is presented by alternate wide areas 69 of electroluminescent material, one area for each ten mile increment of speed and narrow areas do are provided as stated above. The circuits may be closed so that, for example, if the car is proceeding at 65 miles per hour, a narrow area dll between the indicia 60 and 70 will be brightly illuminated and the indicia 60 and 70 will be faintly illuminated. lf the car is traveling at 70 miles per hour, the indicia 70 may be brightly lighted and lanlres. by two less illuminated areas dependent upon the 4 current supplied through the printed circuit pattern. The variation in illumination may be provided by suitable resistors.

rl`he lower instrument aspects may be represented by trie oil level gage. The existence of a low level may be indicated by the glow of a discrete area 8l) of electrolurninescent material formed on the metal plate 46. Current may be supplied to this material by a spring member S2 held by a conductive rivet 34 to a lead of the printed circuit pattern.

For each discrete area of electroluminescent material fifa a signal is received by way oi a terminal 39, a clip 26, a lead of the printed circuit pattern, a clip or a rivet and a spring member 32. The changing current of the signal causes the effected discrete tarea to glow and the current passing through that area is grounded to complete the circuit because the metal plate 16 is grounded. Such ground is by rivets such as the rivets 9h, the heads of which touch the rear side of the metal plate 46. These rivets pass through the pla.e 43 and are connected to ground leads of t e printed circuit pattern.

it will be appreciated that the panel device may be made as a unit and simply inserted through the slot 22 for proper engagement of the printed circuit leads to register and make electrical contact with the clips 26, the latter also acting as means for retaining the laminated structure in its proper position. This is a great advantage in quantity production procedure as heretofore numerous connectons were made in the congested and almost inaccessible space cocealed by the customary instrument panel and particularly as such panels are placed in automobiles.

We claim:

l. A laminated instrument panel device for indicating at least one variable condition, a support having a slot and including a source of variable field power supply, a hood mounted outside said support, said panel device including a rear dielectric support plate carrying a printed circuit pattern, retaining means inside said support, a metal plate grounded to said support and insulated from said pattern by said support plate, multiple discrete areas of electroluminescent material on said metal plate and exposed to view from between said hood and support, a tongued portion of said dielectric support plate extending through said slot `and engaging said retaining means, and conductive means connecting said power supply to said pattern and t0 said discrete areas whereby each of the latter may be caused individually to glow by the application of -said variable eld through said pattern.

2. A laminated instrument panel device as set forth in claim l, the support plate, metal plate and multiple discrete areas of said device being formed as a laminated unit prior to assembly with said support and hood by irn sertion through said slot. Y

3. A laminated instrument panel device for indicating a variable condition such as speed, 4a support rior Said device and including a power source for producing a variable held, a slot in said support, said device including a rear dielectric plate carrying a printed circuit pattern and extending through said slot, a metal plate grounded to said support and insulated from said pattern by said dielectric plate, multiple areas of electroluminescent material on one iside of said metal plate and exposed to View outside said support, a transparent sheet arranged as a protective shield on said material, and conductive means connecting said power source to said pattern said areas whereby said areas may selectively be illuminated by the application of said variable lield to cause said electroluminescent material to glow.

Al. A laminated instrument panel device as set fort in claim 3, including a hood partially surrounding said panel device and from under which said areas may be viewed, and colored filter materia. in registry with said areas.

5. A laminated instrument device, a support for said device having a Islot, retaining means inside said support in alignment with said slot and including a power source and ground connections, a rear dielectric plate extending through said slot and carrying a printed circuit pattern connected-to said power source, a metal plate separated 5 from said pattern by said rear dielectric plate and connected to said ground connections, transparent material, multiple areas of electroluminescent material on one side of said metal plate between the latter and said transparent material and exposed to view through the latter 10 References Cited in the le of this patent UNITED STATES PATENTS 2,698,915 Piper Jan. 4, 1955 2,881,344 Michlin Apr. 7, 1959 2,958,762 Cheney Nov. 1, 1960 

1. A LAMINATED INSTRUMENT PANEL DEVICE FOR INDICATING AT LEAST ONE VARIABLE CONDITION, A SUPPORT HAVING A SLOT AND INCLUDING A SOURCE OF VARIABLE FIELD POWER SUPPLY, A HOOD MOUNTED OUTSIDE SAID SUPPORT PLATE CARRYING A PRINTED CIRCUIT PATTERN, RETAINING MEANS INSIDESAID SUPPORT, A METAL PLATE GROUNDED TO SAID SUPPORT AND INSULATED FROM SAID PATTERN BY SAID SUPPORT PLATE, MULTIPLE DISCRETE AREAS OF ELECTROLUMINESCENT MATERIAL ON SAID METAL PLATE AND EXPOSED TO VIEW FROM BETWEEN SAID HOOD AND SUPPORT, A TONGUED PORTION OF SAID DIELECTRIC SUPPORT PLATE EXTENDING THROUGH SAID SLOT AND ENGAGING SAID RETAINING MEANS, AND CONDUCTIVE MEANS CONNECTING SAIDPOWER SUPPLY TO 